Method for realizing efficient extraction of plant raw materials by adjusting solvent proportion on line

Abstract

The invention discloses a method for realizing efficient extraction of a plant raw material by adjusting a solvent proportion on line, and belongs to the technical field of production process control, a solvent recovery unit is used for evaporating and condensing a recovered solvent, then detecting the proportion of the condensed and recovered solvent on line, and conveying the solvent to a solvent blending unit; the solvent blending unit calculates the amount of the added new solvent according to the detection result, the control unit controls a solvent tank of the solvent blending unit to convey the new solvent into a solvent blending tank and uniformly mix the new solvent, the blended solvent is subjected to solvent proportion detection again for proportion confirmation, and then the solvent enters the extraction unit; the solvent proportion is detected in the middle section of the extraction unit, and a new solvent is added into the extraction unit through a solvent tank according to process requirements; the material meal detection unit is used for detecting the material meal of the extraction unit, the extraction process solvent proportion is dynamically adjusted according to the effective component residue condition in the material meal, and then the control unit is used for regulating and controlling the solvent blending unit to adjust the solvent proportion; and continuously producing, and repeating the steps.

Description

Technical Field

[0001] The invention belongs to the technical field of production process control, and in particular relates to a method for realizing efficient extraction of plant raw materials by adjusting solvent ratio online. Background Art

[0002] Plant extracts are active ingredients extracted from plants by physical or chemical methods and are widely used in medicine, health products, cosmetics, food and beverages, etc. With the increasing awareness of health and the growing demand for natural products, the plant extract industry has developed rapidly.

[0003] There are many methods for plant extraction, including solvent extraction, water extraction, supercritical extraction, and enzymatic hydrolysis. Solvent extraction is widely used for its wide application range, low cost, easy scale and continuous production. Using mixed solvents for extraction can usually improve extraction efficiency and selectivity, and achieve efficient extraction. How to control the ratio of extraction solvents to achieve accurate and efficient extraction is a difficult problem in the industry. At present, most companies use the method of precise volume measurement to configure a fixed ratio of mixed solvents before starting extraction. However, the solvents will be consumed to varying degrees during the extraction and recovery cycle, and the solvent ratio cannot be kept fixed. In addition, the composition of plant extract raw materials of different varieties, origins, and years will also change. If a fixed ratio of solvents is always used, the best extraction effect cannot be achieved. Dynamic adjustment is required to achieve the best extraction effect. In addition, the mixed solvent cannot be completely separated after distillation and recovery, and cannot be used for the next extraction. The rational use of the recovered solvent is both cost-saving and environmentally friendly. Reusing the recovered solvent for the plant extraction production process is the best application for the recovered solvent. Summary of the invention

[0004] The purpose of the present invention is to provide a method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online. By accurately detecting and controlling the mixed solvent ratio at different points using different methods, efficient extraction of plant extracts is achieved, which not only improves the quality of the extracts, but also increases the extraction yield and reduces environmental pollution.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for efficiently extracting plant raw materials by adjusting the solvent ratio online, using a high-efficiency extraction device, comprises the following steps:

[0007] Step A, the solvent recovery unit evaporates and condenses the solvent recovered by the extraction unit, detects the proportion of the condensed and recovered solvent online, and transports it to the solvent preparation unit;

[0008] Step B, the solvent preparation unit calculates the amount of new solvent to be added according to the test results, controls the solvent tank of the solvent preparation unit through the control unit to transport the new solvent to the solvent preparation tank and mix it evenly, and the prepared solvent is tested for solvent ratio again to confirm the ratio, and then enters the extraction unit;

[0009] Step C, detecting the solvent ratio in the middle section of the extraction unit, and adding new solvent from the solvent tank to the extraction unit according to process requirements;

[0010] Step D, the meal detection unit detects the meal of the extraction unit, and dynamically adjusts the ratio of the extraction solvent according to the residual effective ingredients in the meal, and then adjusts the solvent ratio by controlling the solvent blending unit through the control unit;

[0011] Step E: Continuous production, repeat the above steps, and keep the solvent ratio consistent with the process requirements;

[0012] The high-efficiency extraction device comprises an extraction unit, a solvent recovery unit, a plurality of solvent ratio detection units, a solvent blending unit, a meal detection unit and a control unit.

[0013] A further improvement of the technical solution of the present invention is that: the extraction unit is connected to the solvent recovery unit, the solvent recovery unit is connected to the solvent ratio detection unit 1 and the solvent preparation unit in sequence, the solvent preparation unit is connected to the solvent ratio detection unit 2 and the meal detection unit in sequence, and the control unit uniformly controls the extraction unit, the solvent recovery unit, several solvent ratio detection units, the solvent preparation unit, and the meal detection unit.

[0014] A further improvement of the technical solution of the present invention is that: the extraction unit includes a drag chain extractor or a horizontal rotary extractor to extract effective ingredients, the solvent recovery unit includes a rising film or falling film device, a condensation device to evaporate and recover the solvent; the solvent ratio detection unit includes a density meter, a refractometer or a near-infrared spectrometer to detect the ratios of different solvents in the mixed solvent; the meal detection unit includes a near-infrared spectrometer; the control unit includes an industrial computer, an automatic valve and an infusion pump, the solvent preparation unit includes a plurality of solvent tanks and a solvent preparation tank, the solvent tank is connected to the extraction unit, and the middle section of the extraction unit is connected to the solvent ratio detection unit.

[0015] A further improvement of the technical solution of the present invention is that the solvent ratio is detected respectively after condensation recovery, mixing and in the middle of the extraction unit, and the solvent is replenished in the mixing tank of the solvent mixing unit and the middle of the extraction unit to be mixed to the process requirement ratio.

[0016] A further improvement of the technical solution of the present invention is that: in the solvent ratio detection unit, for the two solvent extraction systems to be detected clean, the solvent ratio detection unit one and the solvent ratio detection unit two use a density meter or a refractometer to detect the solvent ratio, wherein the refractometer is equipped with an ultrasonic cleaning device; for a solvent in which more than two solvents are mixed or contain materials, the solvent ratio detection unit one and the solvent ratio detection unit two use a near-infrared spectrometer for detection.

[0017] A further improvement of the technical solution of the present invention is that the content of effective components in the meal is detected by using a diffuse reflection near-infrared spectrometer.

[0018] The steps for establishing a solvent ratio detection model using a near infrared spectrometer for solvent ratio detection are as follows:

[0019] Step 1) mixing the mixed solvents to be tested in different proportions;

[0020] Step 2) The mixed solvents of different proportions include a mixed solvent in which the maximum proportion of any one solvent is higher than the maximum proportion in the actual production process and a mixed solvent in which the minimum proportion of any one solvent is lower than the minimum proportion in the actual production process;

[0021] Step 3) drying the corresponding extracts, adding the dried extracts from different batches to the prepared mixed solvents in different proportions, and the extract concentration after dilution is between 0.5% and 5%;

[0022] Step 4) collecting the near infrared spectrum of the solution prepared in the previous step, and establishing a solvent ratio prediction model based on the known solvent ratio.

[0023] A further improvement of the technical solution of the present invention is that the mixed solvent is configured as a new solvent of analytical grade, the solvent types are 2 or more, the proportion of a single solvent is not less than 0.5% at the lowest and not more than 99.5% at the highest, the configuration is carried out by the volume method, and the spectrum is collected by transmission or transflection.

[0024] A further improvement of the technical solution of the present invention is that in step 3), the extract is dried in an oven at a temperature of 50-55° C. until the solvent residue is less than 5 ppm, and the amount of samples added to the same batch of extracts does not exceed 3.

[0025] The further improvement of the technical solution of the present invention is that the preprocessing method is SG smoothing + standard normal transformation, the spectral range is 1050nm-1550nm, the modeling method is PLS, and the number of factors is 4.

[0026] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are as follows:

[0027] The present invention establishes a method for realizing efficient extraction of plant raw materials by online measuring solvent ratio, which not only improves the quality of the extract, but also increases the extraction yield and reduces environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a solvent ratio detection and mixing device;

[0029] Figure 2 It is a flow chart of solvent preparation;

[0030] Figure 3 This is a near-infrared spectroscopy solvent scale model rendering;

[0031] Figure 4 This is the effect diagram of automatic solvent ratio adjustment;

[0032] Among them, 1. solvent preparation tank, 2. solvent tank, 3. solvent recovery unit, 4. extraction unit, 5. control unit, 6. solvent ratio detection unit one, 7. meal detection unit, 8. solvent ratio detection unit three, 9. solvent ratio detection unit two. DETAILED DESCRIPTION

[0033] A device for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online comprises a solvent recovery unit 3, an extraction unit 4, several solvent ratio detection units, a solvent mixing unit, a meal detection unit 7 and a control unit 5, wherein the extraction unit 4 is connected to the solvent recovery unit 3, the solvent recovery unit 3 is connected to the solvent ratio detection unit 1 6 and the solvent mixing unit in sequence, the solvent mixing unit is connected to the solvent ratio detection unit 2 9, the extraction unit 4 and the meal detection unit 7 in sequence, the middle section of the extraction unit is connected to the solvent ratio detection unit 3 8, and the control unit 5 uniformly controls the extraction unit 4, the solvent recovery unit 3, several solvent ratio detection units, the solvent mixing unit and the meal detection unit 7.

[0034] The extraction unit 4 includes a drag chain extractor or a rotary extractor to extract effective ingredients. The solvent recovery unit 3 includes a rising film or falling film device and a condensation device to evaporate and recover the solvent. The solvent ratio detection unit includes a densitometer, a refractometer or a near-infrared spectrometer to detect the ratios of different solvents in the mixed solvent. The meal detection unit 7 includes a near-infrared spectrometer. The control unit 5 includes an industrial computer, an automatic valve and an infusion pump. The solvent preparation unit includes a plurality of solvent tanks 2 and a solvent preparation tank 1. The solvent preparation tank 1 and the solvent tank 2 are both connected to the extraction unit 4.

[0035] The method for realizing efficient extraction of plant raw materials by using an efficient extraction device and adjusting the solvent ratio online comprises the following steps:

[0036] Step A, the solvent recovery unit 3 evaporates and condenses the recovered solvent, detects the proportion of the condensed and recovered solvent online, and transports it to the solvent preparation unit;

[0037] Step B, the solvent preparation unit calculates the amount of new solvent to be added according to the detection result, and controls the solvent tank 2 of the solvent preparation unit through the control unit 5 to transport the new solvent to the solvent preparation tank 1 and mix it. The prepared solvent is tested for the solvent ratio again to confirm the ratio, and then enters the extraction unit 4;

[0038] Step C, detecting the solvent ratio in the middle section of the extraction unit 4, and adding new solvent from the solvent tank 2 to the extraction unit 4 according to process requirements;

[0039] Step D, the meal detection unit 7 detects the meal from the extraction unit 4, and dynamically adjusts the ratio of the extraction solvent according to the residual effective ingredients in the meal, and then adjusts the solvent ratio by controlling the solvent blending unit through the control unit 5;

[0040] Step E: Continuous production, repeat the above steps, and keep the solvent ratio consistent with the process requirements.

[0041] The solvent ratio is tested respectively after condensation recovery, blending and in the middle of the extraction unit, and the solvent is replenished in the blending tank of the solvent blending unit and the middle of the extraction unit to be blended to the ratio required by the process.

[0042] In the solvent ratio detection unit, for the two solvent extraction systems to be detected clean, the solvent ratio detection unit 1 6 and the solvent ratio detection unit 2 9 use a density meter or a refractometer to detect the solvent ratio, wherein the refractometer is equipped with an ultrasonic cleaning device; for the solvent ratio detection unit 1 6 and the solvent ratio detection unit 2 9 in the mixture of more than two solvents or the solvent containing materials, a near-infrared spectrometer is used for detection.

[0043] The steps for establishing a solvent ratio detection model using a near infrared spectrometer for solvent ratio detection are as follows:

[0044] Step 1) Use a pipette to accurately measure different volumes of the solvent to be tested and mix them in different volume ratios.

[0045] Step 2) The mixed solvents of different proportions include a mixed solvent in which the highest proportion of any one solvent is higher than the highest proportion in the actual production process and a mixed solvent in which the lowest proportion of any one solvent is lower than the lowest proportion in the actual production process, and the proportion of a single solvent is not less than 0.5% and not more than 99.5%;

[0046] Step 3) drying the corresponding extracts, adding different batches of dried extracts to the prepared mixed solvents in different proportions, and the extract concentration after dilution is between 0.5% and 5%; the extracts are dried in an oven at a drying temperature of 50-55°C until the solvent residue is less than 5ppm, and the amount of samples added from the same batch of extracts shall not exceed 3.

[0047] Step 4) collecting the near infrared spectrum of the solution prepared in the previous step, and establishing a solvent ratio prediction model based on the known solvent ratio.

[0048] The mixed solvent is a new solvent of analytical grade, with 2 or more solvent types, of which the proportion of a single solvent is not less than 0.5% and not more than 99.5%. The configuration is carried out by the volume method, and the spectrum is collected by transmission or reflection.

[0049] The preprocessing method was SG smoothing + standard normal transformation, the spectral range was 1050nm-1550nm, the modeling method was PLS, and the number of factors was 4.

[0050] The content of effective ingredients in the meal was detected using diffuse reflectance near-infrared spectrometer.

[0051] The actual production examples using the device and method of this application are as follows:

[0052] Example 1: Efficient extraction of capsaicin

[0053] The red capsaicin is extracted from pepper particles using a mixed solvent of n-hexane and ethanol. The solvent ratio is 3 to 3.5:1 for n-hexane and ethanol, the extraction temperature is 60 degrees Celsius, the extractor is a horizontal extractor, and the material-liquid ratio is 1:3. After the extract is concentrated, the solvent is condensed and recovered, and the solvent ratio is detected to be 5.2:1. 3 cubic meters of recovered solvent and 0.35 cubic meters of new ethanol solvent are injected into the solvent mixing tank. After mixing, the mixed solvent ratio of n-hexane and ethanol is 3.02:1. After testing at the extraction port, the actual ratio is 3.1:1. The solvent ratio is detected at the horizontal middle section pump to be 3.7:1, and the total amount of solvent in the horizontal middle section is 9 cubic meters. 0.33 cubic meters of ethanol is added to the system. At this time, the mixed solvent ratio of n-hexane and ethanol is 3.15:1. According to this process, the weight yield is 8.05% and the content yield is 98.14%.

[0054] Example 2: Efficient extraction of capsaicin

[0055] The red capsaicin is extracted from pepper particles using a mixed solvent of n-hexane and ethanol. The optimal ratio of n-hexane to ethanol is 3 to 3.5:1, the extraction temperature is 60 degrees Celsius, the extractor is a horizontal extractor, and the material-liquid ratio is 1:3. After the extract is concentrated, the solvent is condensed and recovered, and the solvent ratio is 4.1:1. 3 cubic meters of recovered solvent and 0.18 cubic meters of new ethanol solvent are added to the solvent mixing tank. After mixing, the solvent ratio is 3.14:1. After testing at the extraction port, the actual ratio is 3.15:1. The solvent ratio is detected at the horizontal middle section pump and is 3.81:1. The total amount of solvent in the horizontal middle section is 9 cubic meters. 0.5 cubic meters of ethanol is added to the system, and the solvent ratio is 3.01:1 at this time. According to this process, the weight yield is 8.12% and the content yield is 98.11%.

[0056] Example 3: Efficient extraction of capsaicin

[0057] The red capsaicin is extracted from pepper particles using a mixed solvent of n-hexane and ethanol. The optimal n-hexane: ethanol ratio is 3:1-3.5:1, the extraction temperature is 60 degrees Celsius, the extractor is a horizontal extractor, and the material-liquid ratio is 1:3. After the extract is concentrated, the solvent is condensed and recovered, and the solvent ratio is detected to be 2.2:1. 3 cubic meters of recovered solvent and 0.75 cubic meters of new n-hexane solvent are added to the solvent mixing tank. After mixing, the solvent ratio is 3.01:1. After testing at the extraction port, the actual ratio is 3.0:1. The solvent ratio is detected at the horizontal middle section pump to be 3.56:1, and the total amount of solvent in the horizontal middle section is 9 cubic meters. 0.2 cubic meters of ethanol is added to the system, and the solvent ratio is 3.23:1 at this time. According to this process, the weight yield is 8.21% and the content yield is 98.21%.

[0058] Example 4: Efficient extraction of capsaicin

[0059] The red capsaicin is extracted from pepper particles using a mixed solvent of n-hexane and ethanol. The ratio of n-hexane to ethanol is 3.5:1. At this time, the residual effective ingredient of the meal is detected to be 0.6%. The extraction temperature is 60 degrees Celsius, the extractor is a horizontal extractor, and the material-liquid ratio is 1:3. In order to improve the extraction efficiency, the ratio of n-hexane to ethanol is changed to 3.2:1 without changing other conditions. After the extract is concentrated, the solvent is condensed and recovered. The solvent ratio is detected to be 4.6:1. 3 cubic meters of recovered solvent and 0.24 cubic meters of new ethanol solvent are injected into the solvent mixing tank. After mixing, the solvent ratio is 3.19:1. After testing at the extraction port, the actual ratio is 3.19:1. The solvent ratio detected at the horizontal middle section pump is 3.42:1, and the total amount of solvent in the horizontal middle section is 9 cubic meters. 0.06 cubic meters of ethanol are added to the system. At this time, the solvent ratio is 3.32:1. According to this process, the weight yield is 8.16%, the content yield is 98.16%, and the residual effective ingredients in the meal are 0.21%.

[0060] Example 5: Efficient extraction of capsaicin

[0061] The red capsaicin is extracted from pepper particles using a mixed solvent of n-hexane and ethanol. The ratio of n-hexane to ethanol is 3.36:1. At this time, the residual effective ingredient of the meal is detected to be 0.45%. The extraction temperature is 60 degrees Celsius, the extractor is a horizontal extractor, and the material-liquid ratio is 1:3. In order to improve the extraction efficiency, the ratio of n-hexane to ethanol is changed to 3.1:1 without changing other conditions. After the extract is concentrated, the solvent is condensed and recovered. The solvent ratio is detected to be 4.2:1. 3 cubic meters of recovered solvent and 0.21 cubic meters of new ethanol solvent are injected into the solvent mixing tank. After mixing, the solvent ratio is 3.14:1. After testing at the extraction port, the actual ratio is 3.13:1. The solvent ratio detected at the horizontal middle section pump is 3.47:1, and the total amount of solvent in the horizontal middle section is 9 cubic meters. 0.08 cubic meters of ethanol are added to the system, and the solvent ratio is 3.11:1 at this time. According to this process, the weight yield is 8.14%, the content yield is 98.23%, and the residual effective ingredients in the meal are 0.17%.

[0062] Comparative Example 1:

[0063] The same batch of pepper raw materials as in Example 4 was used, and a mixed solvent of n-hexane and ethanol was used to extract capsaicin from pepper particles. The optimal n-hexane: ethanol ratio was 3:1-3.5:1, the extraction temperature was 60 degrees Celsius, the extractor was a horizontal extractor, and the solid-liquid ratio was 1:3. After the extract was concentrated, the solvent was condensed and recovered, and the solvent ratio was detected to be 4.2:1. The recovered solvent and new ethanol solvent were injected into the solvent mixing tank. After mixing, the mixed solvent ratio of n-hexane and ethanol was 3.05:1. After detection at the extraction port, the actual ratio was 3.15:1. The solvent was used to continue to extract it, and the weight yield was 7.85%, the content yield was 96.03%, and the effective ingredient residue of the meal was 2.15%.

[0064] Comparative Example 2:

[0065] The same batch of pepper raw materials as in Example 4 was used, and a mixed solvent of n-hexane and ethanol was used to extract capsaicin from pepper particles. The optimal n-hexane: ethanol ratio of the solvent was 3:1-3.5:1, the extraction temperature was 60 degrees Celsius, the extractor was a flat rotary extractor, and the solid-liquid ratio was 1:3. After the extract was concentrated, the solvent was condensed and recovered, and the solvent ratio was detected to be 5.6:1. The recovery solvent and ethanol solvent were injected into the solvent mixing tank. After mixing, the solvent ratio was 3.14:1. After detection at the extraction port, the actual ratio was 3.2:1. The solvent was used to continue extraction, and the weight yield was 7.63%, the content yield was 94.11%, and the effective ingredient residue of the meal was 3.75%.

[0066] Comparative Example 3:

[0067] Using the same batch of pepper raw materials as in Example 5, the pepper particles were extracted with a mixed solvent of n-hexane and ethanol, the optimal n-hexane: ethanol ratio of the solvent was 3:1-3.5:1, the extraction temperature was 60 degrees Celsius, the extractor was a flat-rotating extractor, and the solid-liquid ratio was 1:3. After the extract was concentrated, the solvent was condensed and recovered, and the solvent ratio was detected to be 5.6:1. The recovery solvent and ethanol solvent were injected into the solvent mixing tank, and the solvent ratio after mixing was 3.03:1. After detection at the extraction port, the actual ratio was 3.1:1. The solvent was used to continue the extraction, and the weight yield was 8.85%, the content yield was 98.42%, and the effective ingredient residue of the meal was 0.24%.

[0068] Table 1: Comparison of pepper granule extraction effects

[0069]

[0070] It can be seen from the above examples and comparative examples that effective monitoring and adjustment of the solvent ratio can improve the extraction efficiency of plant raw materials, reduce the residual effective ingredients in the meal, and improve the process stability. Due to the high ethanol content in Comparative Example 3, more other ingredients were extracted, and the content yield was not significantly improved, which affected the product quality and increased the subsequent refining cost.

[0071] These embodiments show that the ratio of mixed solvents can be adjusted to improve the extraction efficiency. Each embodiment is combined with a specific monitoring technology to ensure accurate control and optimization of the extraction process. The above is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be within the protection scope of the present invention.

Claims

1. A method for efficiently extracting plant raw materials by adjusting the solvent ratio online, characterized in that: Use a high-efficiency extraction device, including the following steps: Step A, the solvent recovery unit (3) evaporates and condenses the solvent recovered by the extraction unit (4), detects the proportion of the condensed and recovered solvent online, and transports the solvent to the solvent preparation unit; Step B, the solvent preparation unit calculates the amount of new solvent to be added according to the detection result, and controls the solvent tank (2) of the solvent preparation unit through the control unit (5) to transport the new solvent to the solvent preparation tank (1) and mix the new solvent. The prepared solvent is tested for solvent ratio again to confirm the ratio, and then enters the extraction unit (4); Step C, detecting the solvent ratio in the middle section of the extraction unit (4), and adding new solvent from the solvent tank (2) to the extraction unit (4) according to process requirements; Step D, the meal detection unit (7) detects the meal from the extraction unit (4), dynamically adjusts the ratio of the extraction solvent according to the residual effective ingredients in the meal, and then adjusts the solvent ratio by controlling the solvent blending unit through the control unit (5); Step E: Continuous production, repeat the above steps, and keep the solvent ratio consistent with the process requirements; The high-efficiency extraction device comprises an extraction unit (4), a solvent recovery unit (3), a plurality of solvent ratio detection units, a solvent blending unit, a meal detection unit (7) and a control unit (5).

2. A method for efficiently extracting plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The extraction unit (4) is connected to the solvent recovery unit (3), the solvent recovery unit (3) is connected in sequence to the solvent ratio detection unit 1 (6) and the solvent preparation unit, the solvent preparation unit is connected in sequence to the solvent ratio detection unit 2 (9), the extraction unit (4) and the meal detection unit (7), and the control unit (5) performs unified control on the extraction unit (4), the solvent recovery unit (3), the plurality of solvent ratio detection units, the solvent preparation unit and the meal detection unit (7).

3. A method for efficiently extracting plant raw materials by adjusting the solvent ratio online according to claim 2, characterized in that: The extraction unit (4) includes a drag chain extractor or a horizontal rotary extractor for extracting effective components; the solvent recovery unit (3) includes a rising film or falling film device and a condensation device for evaporating and recovering the solvent; the solvent ratio detection unit includes a densitometer, a refractometer or a near-infrared spectrometer for detecting the ratios of different solvents in the mixed solvent; the meal detection unit (7) includes a near-infrared spectrometer; the control unit (5) includes an industrial computer, an automatic valve and an infusion pump; the solvent preparation unit includes a plurality of solvent tanks (2) and a solvent preparation tank (1); the solvent tank (2) is connected to the extraction unit (4); and the middle section of the extraction unit is connected to the solvent ratio detection unit 3 (8).

4. The method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The solvent ratio is tested respectively after condensation recovery, blending and in the middle of the extraction unit, and the solvent is replenished in the blending tank of the solvent blending unit and the middle of the extraction unit to be blended to the ratio required by the process.

5. The method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: In the solvent ratio detection unit, for the two clean solvent extraction systems, solvent ratio detection unit one and solvent ratio detection unit two use a density meter or a refractometer to detect the solvent ratio, wherein the refractometer is equipped with an ultrasonic cleaning device; for a mixture of more than two solvents or a solvent containing materials, solvent ratio detection unit one and solvent ratio detection unit two use a near-infrared spectrometer for detection.

6. The method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The content of effective ingredients in the meal was detected using diffuse reflectance near-infrared spectrometer.

7. The method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 1, characterized in that: The steps for establishing a solvent ratio detection model using a near infrared spectrometer for solvent ratio detection are as follows: Step 1) mixing the mixed solvents to be tested in different proportions; Step 2) the mixed solvents of different proportions include a mixed solvent in which the maximum proportion of any one solvent is higher than the maximum proportion in the actual production process and a mixed solvent in which the minimum proportion of any one solvent is lower than the minimum proportion in the actual production process; Step 3) drying the corresponding extracts, adding the dried extracts from different batches to the prepared mixed solvents in different proportions, and the extract concentration after dilution is between 0.5% and 5%; Step 4) collecting the near infrared spectrum of the solution prepared in the previous step, and establishing a solvent ratio prediction model based on the known solvent ratio.

8. The method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 7, characterized in that: The mixed solvent is a new solvent of analytical grade, with 2 or more solvent types, of which the proportion of a single solvent is not less than 0.5% and not more than 99.5%. The configuration is carried out by volume method, and the spectrum is collected by transmission or reflection.

9. The method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 7, characterized in that: In step 3), the extract is dried in an oven at a temperature of 50-55° C. until the solvent residue is less than 5 ppm. No more than 3 samples are added to the same batch of extracts.

10. The method for achieving efficient extraction of plant raw materials by adjusting the solvent ratio online according to claim 7, characterized in that: The preprocessing method was SG smoothing + standard normal transformation, the spectral range was 1050nm-1550nm, the modeling method was PLS, and the number of factors was 4.

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